u/DWilson225

I removed my harmonic balancer from my engine last night, in preparation for replacing my timing gears; timing chain, and chain guides, and because I'm an idiot who didn't take the time to read the harmonic balancer puller instructions, I think I kind of messed up the threads inside the crankshaft, where the harmonic balancer bolt goes into. The bolt is hard to get started, and it turns about 1½-2 turns before the crankshaft starts turning. I need to try to restore/ repair the threads, and Google says the correct tap size would be 5/8-18 UNF (fine thread). But, Google also told me the correct socket size to remove the bolt was 32mm, and that's incorrect - it was a 31mm socket.

Anyone know if 5/8-18 UNF (fine thread) is correct?

Also, I have never before in my life used a tap or a die, and I don't know much about them. My understanding is that a thread chaser and a tap are different, and I should first try a thread chaser?

I'm going to replace my timing chain & gears on my 2002 Dakota's 3.9L V-6, and I'm wondering if anyone knows the correct size socket needed to remove the bolt in the harmonic balancer? I get conflicting answers all over the place for that info: 1⅛; 1¼: 31mm, and 32mm.

Anyone have any idea what's correct?

Who on here has mechanical experience removing and installing cylinder heads?

I'm currently involved in a major mechanical project on my 2002 Dakota SXT (3.9L V-6) that got WAY bigger than I was originally planning on. Now, I have a cylinder head (driver's-side) that's got a broken exhaust manifold bolt in it (I didn't break it; it was already broken when I went to remove the exhaust manifold, and it was broken BELOW the top of the bolt hole, so I don't think a nut could be welded in it, and I don't have a welder anyway). On top of that, I have a bolt extractor that broke off inside the bolt hole. I called two automotive machine shops and neither said they would touch it.

So, I'm thinking I'm just going to buy a new (well, reconditioned) cylinder head and replace the old one. They're less expensive than I thought (roughly $295 each at O'Reilly Auto Parts for reconditioned heads with new valves; valve stem seals, and valve springs). So, a few questions, because I've never done anything with cylinder heads:

1. How do I remove the cylinder head? I mean, I already have the engine half dis-assembled and I know how to remove the cylinder head bolts, but what's involved before actually lifting the head off the block? Do I just remove the nuts on the rocker arms and lift them off? How do the pushrods come out? Do you just pull them out? Is there any rotating of the crank while doing any of this?

2. I have all the exhaust manifold bolts out on the passenger-side, but I'm guessing it's best to replace both heads at the same time (the vehicle currently has 111,000 miles on it)?

3. How do I install the new cylinder heads? Does the crank need to be rotated while installing the pushrods and rocker arms? How do the pushrods install? Just place them in their bores (sorry if any of these questions are stupid, but as I said, I've never removed/installed heads before)?

4. I'm also replacing the timing chain/gears - is that a totally separate procedure? I mean, it doesn't matter if the timing/front cover is installed or not to remove the heads, correct?

Thanks in advance to anyone who can provide me with some tips!